The 0.5 percent gain the Commerce Department reported Friday exceeded the 0.3 percent rise economists had expected. Strength came from a surge at general-merchandise stores. These include big chains such as those owned by Wal-Mart Stores Inc. Excluding autos, sales rose 0.6 percent.

Economists caution, though, that the spending increases seen since summer could falter as the jobs crisis weighs on a fledgling recovery.

Some analysts said the unsettled global economy is eroding confidence that the United States can sustain a recovery from the worst recession in decades.

Many economists cautioned that retail sales were likely to fall in February because of the impact of winter storms that have hit most of the country in the past week.

The increase in retail sales in January followed a 0.1 percent decline in December. The December figure was revised up from an initial report that sales fell 0.3 percent that month. In November, sales had surged 2 percent.